doc NERDTreeAddPathFilter()

doc/NERD_tree.txt

@@ -34,6 +34,7 @@ CONTENTS                                                   *NERDTree-contents*
     4.The NERD tree API.......................|NERDTreeAPI|
         4.1.Key map API.......................|NERDTreeKeymapAPI|
         4.2.Menu API..........................|NERDTreeMenuAPI|
+        4.3.Menu API..........................|NERDTreeAddPathFilter()|
     5.About...................................|NERDTreeAbout|
     6.Changelog...............................|NERDTreeChangelog|
     7.Credits.................................|NERDTreeCredits|
@@ -1173,6 +1174,24 @@ Where selecting "a (s)ub menu" will lead to a second menu: >
 When any of the 3 concrete menu items are selected the function "SomeFunction"
 will be called.
 
+------------------------------------------------------------------------------
+4.3 NERDTreeAddPathFilter(callback)                   *NERDTreeAddPathFilter()*
+
+Path filters are essentially a more powerful version of  |NERDTreeIgnore|.
+If the simple regex matching in |NERDTreeIgnore| is not enough then use
+|NERDTreeAddPathFilter()| to add a callback function that paths will be
+checked against when the decision to ignore them is made. Example >
+
+    call NERDTreeAddPathFilter('MyFilter')
+
+    function! MyFilter(params)
+        "params is a dict containing keys: 'nerdtree' and 'path' which are
+        "g:NERDTree and g:NERDTreePath objects
+
+        "return 1 to ignore params['path'] or 0 otherwise
+    endfunction
+<
+
 ------------------------------------------------------------------------------
 NERDTreeRender()                                            *NERDTreeRender()*
     Re-renders the NERD tree buffer. Useful if you change the state of the
@@ -1203,6 +1222,7 @@ Next
     - add 'scope' argument to the key map API
     - add NERDTreeCustomIgnoreFilter hook - needs doc
     - add magic [[dir]] and [[file]] flags to NERDTreeIgnore
+    - add support for custom path filters. See :help NERDTreeAddPathFilter()
 
 4.2.0
     - Add NERDTreeDirArrows option to make the UI use pretty arrow chars