Can the values of 2 or more fields be combined in a single field?

Set the Type for the field that you want to store the combinded value to “Fixed”.

In the template setting for that field, you can enter the keyword %FIELD#% (where # is the field number) and the keyword will be replaced with the value of the designated field when it is saved.

For example, to combine your first 2 fields into third, inserting a comma between them, set the template for field 3 to:
%FIELD1%,%FIELD2%