It is possible to retrieve the Stock Item Quantity in Secondary Units as shown below:
1. If the field is of Type Quantity, then we can use the in-built template available Qty Secondary Field which is of Type : Quantity : Secondary Units.
Example:
[Field: TSPL FFE SecQty Qty Field]
Use : Qty Secondary Field
Set As : $BilledQty
2. If the field needs to be of Type String, then we have to convert the Quantity into String and use the Format Secondary along with it to get Quantity in Secondary Units.
Example:
[Field: TSPL FFE SecQty Str Field]
Use : Name Field
Set As : $$String:$ActualQty:Symbol,Secondary
Where the Format Symbol specifies the symbol in units like kgs, nos, etc. and Format Secondary displays the Quantity in Alternate units.