Thanks for your revert, but its not working.
I tried overlaying /libs/cq/gui/components/authoring/clientlibs/assetfinder/js/image/ImageAssetPanel.js with below change and its working. Now, while authoring any page, in touch UI editor in AEM 6.3, under Toggle Side Panel --> Assets, only images under content/dam/sales folder will be shown.
self.setSearchPath = function (spath) {
//searchPath = spath;
searchPath ='/content/dam/sales;
};
Could you please let me know who is setting/calling searchPath ? so that, I can pass/change the search path, instead of hard coding in setSearchPath function.
Thanks in Advance