Funnel Workspaces come with four default dimensions: Traffic source, Media type, Campaign and Paid/Organic. Each of these uses a specific set of built-in rules for grouping your data (which you can override to suit your needs). 

Here's how they work:

For data from the connected ad accounts, Traffic source retrieves its value from the name of each of the ad platforms. This means that all data from Facebook will be labeled Facebook, all data from X Ads will be labeled X Ads, etc.

The data from Google Analytics gets labels depending on what ad platforms are connected. For example, if you have a Facebook ad account connected there will be a rule that sets the label Facebook on all Google Analytics data where GA Source = Facebook. Regardless of what ad platforms you have connected there will also be a rule that sets the label Direct on all Google Analytics data matching GA Source = (direct) and GA Medium = (none).

For data from the connected ad accounts, Media type retrieves its value from the "type" of each of the ad platforms. This means that all data from Facebook and X Ads will be labeled Social, all data from Tradedoubler and HasOffers will be labeled Affiliate, all data from AdRoll and Criteo will be labeled Display, etc. The exceptions here are Google Ads and Bing, which can be Display, Search or Price comparison.

The data from Google Analytics gets labels depending on what ad platforms are connected, identified by the value of GA Source and labeled using the ad platform type mentioned above. For example, if you have a Facebook ad account connected there will be a rule that sets the label Social on all Google Analytics data where GA Source = Facebook.

Regardless of what ad platforms you have connected there will also be generic rules that label your Google Analytics data as Display, Search, Social, Affiliate, Price comparison, Email, Referral or Direct depending on the values of GA Source, GA Medium and GA Campaign.

For data from the connected ad accounts, Campaign will be labeled using the first 100 characters of the native dimension that best matches the 'campaign' concept for the data source.  For most data sources there is a native dimension called 'campaign', but some data sources use different names, for instance, Funnel uses the 'Directory' dimension from Capterra as 'campaign'. Some data sources do not have a campaign dimension at all.
The data from Google Analytics will be labeled using the first 100 characters of the GA Campaign value.
These default rules can be overridden if you'd prefer a different setup.

This means that if you:

you will get the Campaign value “My campaign” in Funnel with data both from the Facebook ad account and from Google Analytics.

All data from the connected ad accounts will be labeled 'Paid' for Paid/Organic. For data from Google Analytics, data with GA Medium = 'organic', GA Medium = 'referral' or GA Medium = (none) will be labeled 'Organic'. All other data from Google Analytics will be labeled 'Paid'.