Sorry I mean Feature Dataset. We have an SDE database with more than 1000 Feature classes and tables. most of the FC are inside Feature Datasets.. So when we get a call for an user asking for the location of a FC it will be very helpfull to have a tool to search for a FC.
You can use the script below in ArcCatalog's python window (Change fcName and pathToSDEConnectionFile)
# Feature Class Name (E.g. TestDB.DBO.TestPolygonFeatureClass)
fcName = 'TestGDB.DBO.TestPolygonFeatureClass'
# Path to the sde connection file
pathToSDEConnectionFile = r'C:\tmp\sdeConnections\localhost.sde'
arcpy.env.workspace = pathToSDEConnectionFile
datasets = arcpy.ListDatasets(feature_type='feature')
datasets = [''] + datasets if datasets is not None else 
for ds in datasets:
for fc in arcpy.ListFeatureClasses(feature_dataset=ds):
if ( fc.upper() == fcName.upper()):
print('Feature Class ' + fc + ' found in ' + ds + ' Dataset')