In Business Rules, you can transform values, e.g., you get the EXIF values and extract a specific value like geo point and transform this into a tag you can assign from a list.

You can request values from the Content, the metadata, or audit information. You request those values from implicitly defined variables. You can use these variables in transformations or actions to copy/extract/transform values and store them in another field. The implicitly defined variables are:

$$content$$ to access the Content schema data of a metadata item means the virtual item content or, e.g., Exif, IPTC, DublinCore information for files. 

$$metadata$$ access to the layer schema data of a Content Item. You get access to all values from fields in assigned Layers. 

$$audit$$ to access audit information like the creating user (including user details name, first name, email), modifying user (including user details name, first name, email), modification date, creation date, or information about the owner (first name, last name, email).

When setting a variable the prefix $ must not be used. Only for accessing it like here in input. 

Available Audit Information about Users

Creating User Information

modifiedByUser

id

modifiedByUser

firstName

modifiedByUser

lastName

modifiedByUser

emailAddress

modifiedByUser

isDeleted

Creating User Information

createdByUser

id

createdByUser

firstName

createdByUser

lastName

createdByUser

emailAddress

createdByUser

isDeleted

Owner Information

ownedByUser

id

ownedByUser

firstName

ownedByUser

lastName

ownedByUser

emailAddress

ownedByUser

isDeleted

"transformationGroups": [
	{
			"inputs": [
				"$$audit$$"
			],
			"transformations": [
				{
					"kind": "TakeDictionaryValueTransformation",
					"key": "createdByUser",
					"traceRefId": null
				},
				{
					"kind": "TakeDictionaryValueTransformation",
					"key": "firstName",
					"traceRefId": null
				}
			],
			"storeIn": "productManagerFirstName",
			"traceRefId": null
    }]
CODE
"transformationGroups": [
  {
		"inputs": [
				"$$audit$$"
			],
			"transformations": [
				{
					"kind": "TakeDictionaryValueTransformation",
					"key": "ownedByUser",
					"traceRefId": null
				},
				{
					"kind": "TakeDictionaryValueTransformation",
					"key": "firstName",
					"traceRefId": null
				}
			],
			"storeIn": "owner",
			"traceRefId": null
		}
]
CODE