Configure reference qualifier to show only records which are not already used in other record

[Chandler2]

I have a custom reference field "Choose your demand" on task table which refers to dmn_demand table. Now, once I have selected a demand record in field "Choose your demand",

Option 01: I don't want already selected records to be showing up in magnifying glass next time someone is trying to select a value

OR

Option 02: If someone selects a demand record which has been selected already in another task record, show an error message that this demand has already been used in "xyz(name of task)" so please select a different demand.

Please suggest for both. (Although I think option 01 is a better way to go)

Thanks

[jleach67]

Hi Chandler2,  did any of the options provided work for you?

Thanks