Sorry about the vagueness of my questions.
I need my report to display particular data stored in the database under a particular location, and the parameter I would use is based on that locations number, so in this case, the locationtype column = 21, which is for the location of Hertfordshire storage.
So when the parameter is used it will select any column data that had the locationtype of 21. But for my case the location of Hertfordshire storage as been added 4 times under four different locationtype numbers, so what I am trying to do is, when the parameter is selected, it displays all data related to those four locationtypes.
Does this make more sense?