I don’t have Revit/Dynamo in front of me at the moment- but have a vague recollection that pipes do not have a ‘level’ parameter but do have one called ‘reference level’
If so, you could get all pipe category objects then groupfilter by this parameter
@Andrew_Hannell@Cahit_Okten There is a custom node from @john_pierson Rhythm package called “All Pipes at Reference Level” use that to collect all pipes from level.