Defining strict trust condition on cloud roles for oidc claims

I am using OIDC with GitHub Actions workflow and I want to tighten what branch in my repo can request an access token from my cloud provider.Only when the trust configuration is a match then my cloud provider can issue the temporary token to the workflow.

Filtering for pull_request events : repo:octo-org/octo-repo:pull_request
my understanding is that configuring this condition will successfully request token on pull request to any of my branches.I would like to be more strict so that my cloud provider only issue temporary token to the workflow if the pull request is on a specific branch that i configured in the trust conditions. for example ,I want to configure the condition so that token can be issued if the pull request is on my Dev branch so if someone tries to do a pull request on testing branch then it will fail.please how can I modify repo:octo-org/octo-repo:pull_request to reflect what i want to achieve?