Passing one parameter from one flow to another can be done easily. For the purpose of this example let's define F1 as the first flow, the source flow, and F2, the destination flow.
Step 1: Capture the value.
When recording the Flow F1 store the value you want to use in the Flow F2 using the Store button on the recorder widget;
Open the Store step and go to the Step Configuration tab;
Modify the parameter name to make it meaningful and unique;
Enable the Export data as variable flag.
You can find a quick video instruction bellow:
Step 2: Go to the Data Set of the Flow F2 and identify the path to the parameter value you want to pass.
Go to the Flow F2;
Open the Data Set tab and select the target Data Set;
Double click on the cell of the parameter, where you want to reuse the value from the Flow F1 and type the following formula:
PARAMETER_NAME - is a name of the parameter from the Flow F1
You can find the video below: