This Outliner for Maya allows you to more easily organize your scene with easier access to Maya's built-in filters, and a filter-builder to make your own advanced custom filters.
Selection Filters - See shaders, textures and more, only relevant to the model you're working on.
Script Filters - Custom Python-filters allow for more complex filters. Filter based object attributes, or only show a list of geometry with NGons in them.
Copy the "ks_nodeOutliner" folder into a directory where Maya can access scripts and python plugins.
Example - Windows: C:\Users\USERNAME\Documents\maya\2019\scripts
Then run the following Python command inside Maya:
from ks_nodeOutliner import ksNodeOutliner