If you are in the Editor perspective switch to the XSLT Debugger perspective or XQuery
Debugger perspective with one of the actions (here explained for XSLT):
Menu Window
> Open perspective
> XSLT Debugger or the toolbar button XSLT Debugger
Menu Document
> XML Document
> Debug Scenario or the toolbar button Debug Scenario. This action
initializes the Debugger perspective with the parameters of the transformation scenario.
Any modification applied to the scenario parameters (the transformer engine, the XSLT
parameters, the transformer extensions, etc) will be saved back in the scenario when
exiting from the Debugger perspective.
Select the source XML document in the XML source selector of the Control toolbar. In case of
XQuery debugging if your XQuery document has no implicit source set the source selector
value to NONE.
Select the XSLT/XQuery document in the XSLT/XQuery selector of the Control toolbar.
Set XSLT/XQuery parameters from the button available on the Control toolbar.