Depending on what is the type of field "Room Name" the setup might not be correct. Option "Lookup value field" on the Lookup Select Box variable indicates which will "provide" the value for a choice to store in the database. If "Room Name" is a reference, then Lookup value field has to be Sys ID. Only if Room Name is a field of type Choice, or String with option to display as choice, would this setting be possibly correct.
You should also specify a value in Lookup label field(s). That decides which field(s) of the table providing the choices (in this case Room type) to list in the Lookup Select Box when someone "drops-down" the Select Box. Not knowing the structure of work hub room, it is har for me to say which fields are appropriate/valid.
Lastly, if you allow me an advice, that also ties into how to "build" in harmony with ServiceNow established practices, but also generally accepted best practices, don't name fields Something Name. Unless it is really a name that is stored in that field. But even then, if you have a table Something, you should create a reference field instead and name it Something.
E.g. if you open an Incident record and look at the form/table, you will notice that it contains references to other records in other tables - like Problem (reference to table Problem) or Opened by (reference to table User) - on those fields are not called Problem Number or Opened by Name, even though that is what is displayed in those fields: the number of the reference problem record and the name of the user that opened the Incident.
Using and attribute of a record to refere to a record is also bad, because it will not be possible to differentiate between when someone references the Room Name vs the Room record (both will be called Room Name if you name references like that).
