Field Group Name is an undocumented feature that has been around since version 3.6.  Field group name is essentially a property from the Edit Field element window that describe the name of a Group the field element belongs to.  It is a way of categorizing field elements.  By itself the property is not in any way a feature but when used in conjunction with Conditional Visibility it is time saver.

Pretty much all Enterprise Forms field elements have this property, FieldGroupName, and is generally located at the bottom of the General Tab of the Edit Field Element screen (as shown below). 

How to use FieldGroupName with Conditional Visibility

Conditional Visibility is the ability to show/hide or enable/disable a field based on certain conditions such as values from other form fields or workflow state etc.  Generally each conditional visibility definition can only be applied to the field element that has conditional visibility defined. 

So where does FieldGroupName comes in?  Within the Conditional Visibility definition tab there is a property called VisibilityGroupName (shown in image below).  This property accepts one or more FieldGroupNames which basically is used for applying the conditional evaluation to all the field elements belonging to the provided FieldGroupName(s).  To provide more than one FieldGroupName, simply separate each value by a coma (,) i.e.  Group1,Group2,Group3

As an example, lets say we have 3 field elements in our form, FieldA, FieldB, FieldC and FieldD with FieldC and FieldD have the same FieldGroupName of “Group1”.  We then define conditional visibility for Field3 with settings as shown in image below. 

When conditional visibility kicks in, FieldC will become visible if FieldA equals to FieldB.  In addition FieldD will also become visible because FieldD is part of the FieldGroupName “Group1” as defined via the VisibilityGroupName property.

As you can see, for forms with significant number for field elements, not only this is great time saver it also provides an easier way of managing conditional visibility for multiple field elements.