This dialog allows selecting attributes and/or variables to include them in some section of an object (form, rules, events, etc.).
The dialog will be opened if you drag the Attribute/Variable icon to anywhere in a form:
...and also if you select: Insert/Attribute in the GeneXus menu bar to insert attributes or Insert/Variable to insert variables, when you are positioned on an object section.
You can select multiple lines by clicking on them while holding down the Shift or Ctrl keys. When the selection is completed, the selected attributes and/or variables will be inserted where you were located (form, events, source, etc.) when you invoked this dialog.
You can filter to limit the search, as shown in the following image:
Other ways to insert Attributes or Variables:
By pressing Ctrl+Shift+A to insert attributes or Ctrl+Shift+V to insert variables
By dragging & dropping one or several attributes from the Work With Attributes Window to the Web Form (if you drag & drop with the right button of your mouse, you can choose if you want the attributes to be inserted as a grid, freestyle grid or table).