Our Service Desk logs many different types of Request. At the time of logging, these Req_Types also have Req_Group selected against the Req_Type. 

How can I restrict what Req_Groups are availabe to select in accordance to the parent Req_Type?

Eg.

If Req_Type = Fault, the applicable Req_Groups could be “A, B C”.
If Req_Type = HSE, the applicable Req_Groups could be “D, E, F”
etc.

I tried assigning the Req_Group a Parent of Req_Type and then against the relevant Req_Groups added the parent value of “Fault”, but that didn’t work.

Could someone please provide a little guidance if this can be achieved.

Additionally,

I would like to limit the options of Task Status depending upon the Task_Template selected. Is that possible?.