If you want to edit one of your Custom Lists, you can make changes to an already created Custom List and save them to the current Custom List, or save it as a completely new and separate Custom List.
To do so, navigate to the Lists section 
via the advanced toolbar, then:
EITHER:
- In the top left corner, click on
. - In the resulting drop-down menu, hover over "My Lists." This will open a list of every Custom List you've created.
- In the resulting drop-down menu, hover over the name of the List you want to edit.
- Click
to the right of the List’s name.
- In the resulting window, add or remove any necessary filters, then click
.
OR:
- In the top right corner, click on the
. - In the resulting window, add or remove any necessary filters, then click .
- Once you make any updates to the filters on your List, you will see a “Edited” drop-down appear at the top of the List to the right of the List picker.
- In the resulting drop-down:
- Click “Save” to save the changes made on the current Custom List.
- Click “Save As” to save the changes made as a separate Custom List.
- In the resulting window, update the name of the List and make any other changes.
- When you’re done click to create a new Custom List.