Thank you both of you. It worked out when I created a custom rule for a role to modify certain records only when the assigned to Dropdown field was equal to the user.
Ryan, unfortuantely I couldn't figure out your solution. When I go to create a dynamic form rule. I can select when user, but the only option at that point is to select "is in the role" or "is not in the role". It's not possible to relate the user to the value in "Assigned To" Field. Also true the opposite way when Assigned to "is equal to" the next field doesn't give me an option of user. This would have been my preferred solution, but since it didn't work out. The other way works too.
Thanks for your help!
