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To use the Saved Filters tree, the user will want to make sure they set it as visible in the Select Tree... drop-down. Once visible, the user can select it in the Available Trees panel to create their custom filters to save and reuse. To see example, look at Tag Bundles Tree.
New Saved Filter/Add
To create a Saved Filter, the user would select the parent tree and then either click on the plus sign 
and then selecting "New Saved Filter" or the Add button on the grid view side. The user can also create a new one while having a Saved Filter selected.
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