Autocomplete elements in course participant filters obscure text inputs

When using course participant filters that use autocompletes (most of them, e.g. Roles & Groups) the suggestions list obscures the actual text input making it impossible for a user to see what they are typing:

When autocomplete elements are used elsewhere, the suggestions typically fall below the text input so you can see both at once

Seems to be an issue doing back to current 39 stable branch, I found while looking at MDL-70995