Download the script on both Active/Standby BIG-IQ CM(s).
bash
mkdir /shared/scripts
cd /shared/scripts
curl https://raw.githubusercontent.com/f5devcentral/f5-big-iq-pm-team/master/f5-bigiq-branchRuleManager/Create_BranchRule_With_CustomExpression.py > Create_BranchRule_With_CustomExpression.py
chmod +x Create_BranchRule_With_CustomExpression.py
cd /shared/scripts
./Create_BranchRule_With_CustomExpression.py