Using Pose Library:

The apply option panel is at the bottom of the PoseAnim Library UI.

Item Clicked:

Library Management: The mode is for managing the library, in this mode, you can ctrl/shift select multiple items, edit them, upload/download , copy/move and delete them.

Simply Apply: In this mode, single clicking a pose item will actually apply the pose.

Advanced Apply: In this mode, you have to select one pose item first, tweak the apply options, then click the "Advanced Apply" button.

The options describe below are only available in Simple Apply mode and Advanced Apply mode.

[Ctrl Click : %]: Input a percentage, which will decide, when you hold ctrl key, and press the item button in simple apply mode, the percentage the pose will be applied.

In advanced mode, this percentage will affect the percentage you apply the pose, when you hold ctrl key and press on the "Advanced Apply" button.

Namespace Use: Selection Namespace: Use the namespace of the scene selection, map the objects in the pose, get the target objects that will be applied the pose.

Say you select CharB:body, and the controllers involved in pose data are CharA:hand, CharA:feet, then the CharB:hand and CharB:feet will be applied pose.

Pose Namespace: Do no namespace mapping, apply pose to the controllers recorded in the pose data.

Custom: Enable the input field at the right side, where you could input a namespace, or input the namespce use the "< Selection" button.

Then tool will use the namespace to map and get the target objects to apply the pose.

Current the PoseAnim Library tool grabs the target objects to apply pose/anim via their names.

So when apply a pose, if you want to apply to the same the pose/anim are created, you actually don't need select anything.

Options below only available in Advanced Apply mode:

Filter Object: The target object list has been nailed down by the namespace mapping rule above, but we could filter them again:

Unfiltered: Apply to all the target objects mapping from the pose data.  

Only Selected Objects: Only the target objects been selected will be applied.

Ignore Selected Objects:  Only the target objects not been selected will be applied.

Attribute: As the target objects been filtered, we could filter the attribute again:

Unfiltered: Apply the pose to all the attributes of the target objects.  

Only Selected Attrs: Only apply the pose to the selected attributes of the target objects via Maya/MG-Channelbox.

Ignore Selected Attrs:  Only apply the pose to the unselected attributes of the target objects via Maya/MG-Channelbox.

Channelbox Icon: click to decide the tool should get the attributes selected/not selected info from MG-Channelbox or Maya channelbox. Maya channelbox is used by default.

Apply Options: At Current Frame: Apply the pose at current frame.

At Frame Pose Created: Apply the pose at the original frame that the pose was recorded.

Apply in Worldspace: When the pose was created, if the recorded object is transform, the world transformation will also be recorded.

So when applying it, if the target object are transform nodes, this option will make the pose info been applied in world space.

Advanced Apply Button: In Advanced Apply mode, you have to select one pose item first, tweak the apply options, then click this button to actually apply the pose.

The slider below: Drag it to instantly apply the pose in the range 0%~100%.