This is accomplished when you are setting up the Campaign, Fund, or Appeal record.

1. Select the Records page and Select Funds and open a fund
2. Once you have selected and opened your Fund, select the Appeals tab
3. Enter the Appeals and Campaigns you would like associated with the Fund
4. Mark the Limit gift entry to associated appeals checkbox on the Appeals tab. This will prevent you from adding a gift with a particular Fund and then selecting a Campaign or Appeal that is not associated with the fund.

This works the same way when setting up Campaign and Appeal records.