Hi, Andrew 

Thanks for reaching out to us

If i understood your goal,  you would like to manually make a list of available values for filtering in a column,

regardless of which values are in the cells themselves?

If that is the case, we have a solution.

-

- You can manually create values for a column, to use in a filter, ( and for editing),

even there are some values placed together in the same cell, we can "separate them for filtering",

here is an example.

The table pulls the values from all cells, so since you have multiple values together in one cell, it sees it as a unique value.

What you can do is open this column's settings, go to the Data tab. In there, change "Possible values for column" from "Read from table on page load" to "Define values list":

Then, in the "Values list", manually input the individual values that should be included in this column, and that's it. It should allow you to select each value on the filter, as an individual selection.

; here is the resulting filter multiselectbox of this example:

Let me know if that helps.