Use the Hide Row feature. Right-click any rows you want to temporarily hide from view and select ‘Hide Row’ from the drop-down menu. This will filter out these rows. To un-hide them, either click on the filter icon in the Ticker column header and deselect the boxes of the rows you want to see again, or click the active filter in the table header to un-hide all rows.
Premium and Premium Plus users can also use Portfolio Trade Planning to explore alternative versions of a portfolio.