Find Configuration Setting For Marketing Cloud Connect

First, create the Configurations tab

1. Click Setup. 

2. Follow the steps based on your UI:

Salesforce Classic: Under the "Create" category, select Tabs.

Salesforce Lightning: Under the "User Interface" category, select Tabs.

3. Click New.

4. Choose "Configurations" from the Object drop-down menu.

5. Pick any Tab style.

6. Click Next | Next | Save.

Then, Edit the Configurations page layout to include the fields you need:

In Lightning: Setup > Object Manager > Configurations > Page Layouts > Edit > Add in the fields available > Save

In Classic: Setup > Create > Objects > Configuration > Page Layouts > Edit > Add in the fields available > Save

When you then view a configuration in the configurations tab you will be able to see all of the settings as contained on the Settings page within the Marketing Cloud Tab.