Automator Applescript - Use 1 Ask For Finder Item Selection for two different Actions
To refer back to the value of a previous action, you can use the Set Value of Variable action and the Get Value of Variable action as appropriate, e.g.:

Ask for Finder Items action
Set Value of Variable action
Some other action.
Some other action.
Get Value of Variable action
Run AppleScript action
Some other action.

You should also check [√] Ignore this action's input in the Options section of the Set/Get Value of Variable action as appropriate so its action is logically disconnected from the next action.
In the example Automator workflow below, there would be other actions between the Set Value of Variable action and the Get Value of Variable action as wanted.
Note: If the Run AppleScript action is the last action in the workflow, then you do not need to include the return input line of code.