Multiple individual dropdowns, each selection removed from subsequent dropdowns

I've set page up, called documents from firestore and populated the options available (give full list that doesn't change based on selection). I've also tried setting a query on the dropdown filtering selections based on "not equal" works for a single filter but errors if try for two filters. I've also tried to set state variables (as list) and populate these and then link to the dropdown box option and selection to value, but have issues trying to link the option to the variable (not sure how to do this correctly or if this will work).

Potentially there might be a better (or a more obvious way to achieve this such as a multi select dropdown but was wanting have three clear selections on page for user). Any help greatly appreciated.