I'm wondering if the following makes sense. Please note, splitting the information into separate columns is not an option due to too many columns. Column 1: there are more time stamps the column might be sorted by, but it can only be discovered by seeing the dropdown options. Column 2: all the information this column can be sorted by is available at a glance (Name Surname, Job title, Location, another item). Thank you.
Yes this makes sense, but I'd make one change and give two suggestions. I'd change the ascending/descending toggle so that it shows what state is selected with a heavier stroke for the current sort order. Suggestion 1) pull the main data type out of your column headers, so column 1 reads:
Sort date by [ hire / ]
And column 2 reads:
Sort employee by [ name / ]
Suggestion 2) If you'd like the ability to choose more options in the dropdown to be more discoverable then consider reversing the contrast: use white fill in the dropdown with black text.