I'm trying to set up confirmations for one of the forms in gravity forms to give a different thank you page for each different location page, the thank you pages have differed page id's in wordpress. Each location page uses the same form. I set up in the form a hidden field which identifies each different location and named it manager_email. Is there any kind of code or condition I can set in gravity forms to achieve this? I need it to identify by the hidden field manager_email, which location it is, therefore, giving the correct thank you page.
Gravity Forms supports conditional confirmations out of the box. Go to the "Confirmations" page under "Form Settings". At the top you'll see a button to "Add New". Click this to add a new confirmation. On the confirmation edit view at the very bottom will be a section labeled "Conditional Logic" (example). You can use this section to indicate when this confirmation should be used.
In your case, you'd create a separate confirmation for each unique thank you page and then add a condition to each that matches the corresponding location based on your "manager_email" field.