diff --git a/src/valenspy/ancilliary_data/dataset_info.yml b/src/valenspy/ancilliary_data/dataset_info.yml
index 9dc1a9c6..ae49d519 100644
--- a/src/valenspy/ancilliary_data/dataset_info.yml
+++ b/src/valenspy/ancilliary_data/dataset_info.yml
@@ -40,7 +40,10 @@
 hortense:
   ERA5: #Note that there is an aggregation variable here! What to do with this? This is messy as it can not be uniquely identified by the filename!
     root: /dodrio/scratch/projects/2022_200/external/era5/
-    pattern: <domain_id>/<variable_id>/<frequency>/<variable_id_2>_era5_<domain_id_2>_<frequency_2>_<aggregation>_<time_period>.nc
+    pattern: #Warning: patterns should be mutually exclusive to ensure correct parsing of the information from the path. A path should not be able to match two patterns!
+      - <domain_id>/<variable_id>/<frequency>/<variable_id_2>_era5_<domain_id_2>_monthly_<aggregation>_<time_period>.nc
+      - <domain_id>/<variable_id>/<frequency>/<variable_id_2>_era5_<domain_id_2>_daily_<aggregation>_<time_period>.nc
+      - <domain_id>/<variable_id>/<frequency>/<variable_id_2>_era5_<domain_id_2>_hourly_<time_period>.nc
     meta_data:
       source_id: "ERA5"
       source_type: "reanalysis"
diff --git a/src/valenspy/input/esm_catalog_builder.py b/src/valenspy/input/esm_catalog_builder.py
index f894109f..5616aa9e 100644
--- a/src/valenspy/input/esm_catalog_builder.py
+++ b/src/valenspy/input/esm_catalog_builder.py
@@ -110,10 +110,12 @@ def _validate_dataset_info(self):
 
         for dataset_name, dataset_info in self.datasets_info.items():
             key_set = set(dataset_info.get("meta_data", {}).keys())
-            pattern = dataset_info.get("pattern", None)
-            if pattern:
-                for key in re.findall(r"<(.*?)>", pattern):
-                    key_set.add(key)
+            
+            if pattern := dataset_info.get("pattern", None):
+                if isinstance(pattern, str):
+                    pattern = [pattern]
+                #Add keys present in all patterns to the key_set by extracting the identifiers in the pattern.
+                key_set.update(set.intersection(*[set(re.findall(r"<(.*?)>", pat)) for pat in pattern]))                
 
             # Check if all required identifiers are present
             for identifier in required_identifiers:
@@ -172,12 +174,19 @@ def _process_dataset_for_catalog(self, dataset_name, dataset_info):
 
         """
         dataset_root = Path(dataset_info.get("root"))
-        regex_pattern = create_named_regex(dataset_info.get("pattern", None))
-        regex = re.compile(dataset_root.as_posix() + r"/" + regex_pattern)
 
-        dataset_meta_data = dataset_info.get("meta_data", {})
+        if pattern := dataset_info.get("pattern", None):
+            if isinstance(pattern, str):
+                pattern = [pattern]
+
+        regex = [re.compile(dataset_root.as_posix() + r"/" + create_named_regex(pat)) for pat in pattern]
 
-        IC = INPUT_CONVERTORS.get(dataset_name, None)
+        dataset_meta_data = dataset_info.get("meta_data", {})
+        if dataset_IC := dataset_info.get("input_convertor", None):
+            IC = INPUT_CONVERTORS.get(dataset_IC, None) #Use the specified ICs
+        else:
+            IC = INPUT_CONVERTORS.get(dataset_name, None) #Use the dataset name to find the IC
+        
         if IC:
             CORDEX_variable_set = IC.cordex_variables
             variable_set = IC.raw_variables
@@ -188,13 +197,13 @@ def _process_dataset_for_catalog(self, dataset_name, dataset_info):
             for file in files:
                 if file.endswith(".nc"):
                     file_path = os.path.join(root, file)
-                    if match := regex.match(file_path):
-                        file_metadata = match.groupdict()
-                    else:
-                        #Add the skipped file to the skipped files dictionary (create the entry if it does not exist)
-                        if dataset_name not in self.skipped_files:
-                            self.skipped_files[dataset_name] = []
-                        self.skipped_files[dataset_name].append(file_path)
+                    for reg in regex:
+                        if match := reg.match(file_path):
+                            file_metadata = match.groupdict()
+                            break
+
+                    if not match:
+                        self.skipped_files.setdefault(dataset_name, []).append(file_path) 
                         continue
 
                     # Add the file path to the metadata