I'm trying to make a Wiki on SharePoint Online, where each page in the Wiki has a column called "Subject". The column type is Lookup, and it's linked to a list called "List of Wiki Subjects". The list is, eponymously, a simple text list that I want to determine what a Wiki Page's Subject may be set to.
I'm working on the main "landing page" for the wiki now. It has a Web Part for the Wiki Library (which is called "Knowledge Base Wiki Library"), and a SharePoint List Filter Web Part that's also connected to "List of Wiki Subjects".
I would like the end user to be able to select list items from the filter Web Part, and have the Wiki Library Web Part only show items whose Subject columns have the selected items. My problem is, I can't select the Title column as the Value field to filter on in the filter Web Part's properties (see picture): "List of Wiki Subjects" has only one column, called Title (the default only column when I created the list), but I can't filter on the title. If I add another column, i.e. "Title for Filtering", it appears in the "Value field" dropdown, but I want to just filter on the title of the item, and not rely on my site maintainers having to put the same title in 2 different columns when a new subject is added to the list.
I'm pretty new to SharePoint. Is there a better way to do this that I'm missing? Or a way to enable the Title column as a "Value field" option in my Filter Web Part?