Firstly, I would recommend making sure to finalise what information you want to display.
Then with this information, you should have an idea where you can pull the data from,
Hopefully, the information is on the line you are using and can then just pull the information from it,
If it is something else on the drawing that you are linking too,
We must be a bit more creative.
On my P&IDs I have created a custom drawing field Drawing ID for this demo,
I want to display the Drawing ID of the connecting page by my Off page connector,
To do this,
Go to your Project Setup, P&ID DWG Settings, P&ID Class Definitions, Non Engineering Items, Connectors, Off Page connectors.
Select the Edit Block…
In the block editor, to save time, copy another field to the location you want your information.
While the new one is selected, click Assign Format.
Due to the information I am wanting to use being on the drawing itself, I use Select Drawing Properties.
In Category, I selected the Drawing Data Category I created.
Drawing Properties, select Drawing ID.
Select OK then OK again to accept the changes.
Now double click the same text to open the Attribute editor,
In the Tag, after the opening bracket, add an = symbol,
This tells the system, that we are referring to the connected drawing, not the drawing the connector is currently on.
Select OK then OK on the Project Setup.
The Off Page connector should now display your information.
You may need to Save or drop in another connector for the others to update.