Try this, assuming you have a field named ‘FIELD_NAME’ and the field has a value ‘Field Value’
put this in hotspot hidewhen formula.
FIELD_NAME = “Field Value”
The hotspot will be hidden if the value of the field is ‘Field value’ and its visible otherwise.
you must refresh the form every time the value of field has changed or set the field property to "Refresh fields on keyword change " if you are using the other field type (e.g. Combobox, Dialog list)