This should get what you're after. Effectively, it will build up an array of Names from your Excel Table, then check to see if that array of Names contains the Name that was entered in the Form.
My Excel Table for this example is below:
And my super complex form 😉
Below is the full flow. I'll go into each of the actions.
The first three actions are fairly straight forward. When a new response is submitted and Get response details retrieves the output of our Form. List rows present in a table returns all the rows in our Excel Table.
Next, we build up a simple array of Names from our Excel Table data. We use a Select for this using value from List rows present in a table and go into Map to text mode (icon on bottom right as shown by the arrow below) and add the Name field.
This will give us the following output:
[
"Bob",
"Jane",
"Bill",
"Jack",
"Jill",
"Mary"
]
We can then use the output from our Select to check if the array of Names contains the Name we entered in our Form. If it does, we go into the Yes branch, otherwise the No branch.
