Campaign - Workflow - Assign tag based on activity

Campaign - Workflow - Assign tag based on activity

hello.

i am trying to create a workflow that ends up tagging a lead when they click a certain link and sending them into appropriate campaign.

for instance.  in one email i have 2 links.

1 link is for "topic 1"
1 link is for "topic 2"

when the recipient clicks "topic 1", i want to create a tag "topic 1" and send them into a different workflow/campaign "topic 1"

when the recipient clicks "topic 2", i want to create a tag "topic 2" and send them into a different workflow/camapign "topic 2"

how do i add this condition to the email?