Consider below approaches for your requirements:
A. Using Premium Connector:
You can use HTTP action to trigger flow from multiple document libraries/lists in SharePoint.
Follow below articles for detailed steps:
- Deploying a single flow to multiple SharePoint libraries/lists
- Trigger One Flow From Multiple SharePoint Lists
- One Flow to handle them all - how to subscribe to multiple SharePoint lists with one Flow
B. Using Parent-Child flows (Without Premium):
If you have common logic in Power automate flow for all document libraries, you can try this approach:
- Create one parent flow for each document library using SharePoint connector trigger.
- Create another (child) flow which will take inputs from parent flow and has common logic in flow.
- Call child flow from parent flows.
By using this approach, you will have only one flow which executes the common operations. So, maintenance of flow will be easier in this case.
Documentation: Create child flows - Power Automate