Can you expand on what you're trying to do here? What have you tried that didn't work?
It kind of sounds like you have a composite blueprint. Within that blueprint you have two XaaS components you've added to the canvas. So you want to call XaaS component 1, which will create a pool, then XaaS blueprint 2 which will take the output of blueprint 1 and add a member to that pool?
I assume you are also provisioning one or more VMs as part of this blueprint. So the intent is to add the VM(s) you're provisioning to the pool, after creating the pool first?
If what I describe above is the correct scenario, then I think what you should do is move your workflows to the event broker system. You would create a subscription for workflow 1 (create pool) to happen upon machine provisioning (or maybe machine provisioned if you want it to happen after the machine is done building) for the blueprint(s) you want this behavior to happen on. That workflow would read the information from the request and create the pool, then call the second workflow to add the machine to the pool from within the first workflow - this would be a modification of the vRO workflow.
I assume you don't want a separate pool for each VM, so perhaps you want to want to make the main workflow be "Add member to pool" taking a member and a pool name as input. If the pool doesn't exist, create it first, then add to it, but if it does already exist, just add to it.
Alternatively, you could keep the create pool workflow as an XaaS component and make your machines dependent on it so it runs before kicking off provisioning tasks. Then use the event broker subscription idea to grab machine info and add it to the pool after it finished provisioning.
As an aside, I'm not sure what the construct of pool is in this scenario. Is it a logical grouping you created or something in a particular product/system you're interacting with?
