Integrate multiple forms into a single Google Sheet file

If you mean you would like to integrate several forms with the same Google Sheet, that's possible.

When you integrate the form, there's an option there to select which file to use:

Once done, the form's data will be sent to the specific sheet you've configured while setting up the integration.

Also, if you intend to add customizations into each sheet, we highly discourage it as it may break the integration. If there's a need to manipulate the data between the sheets, we recommend duplicating them instead. You can use the IMPORTRANGE function to mirror the data from one sheet to another.

Actually the opposite. I was asking can use multiple google spreadsheets in one form?

Unfortunately, no. It has to be one sheet for every form, so what you're trying to achieve isn't possible.

You would need to manually create data manipulation processes (e.g. IMPORTRANGE) into the Workbook to slice the data from the original sheet to multiple sheets.