Thread is old but I needed this kind of feature in my application and I found a way to do it so I decided to post it if it can help anyone in my situation.
As our device fleet is composed only by Samsung Galaxy Tab 2, I just had to find the file explorer's package name, give the right path and I succeed open my file explorer where I wanted to. I wish I could use Intent.CATEGORY_APP_FILES
but it is only available in API 29.
Intent intent = context.getPackageManager().getLaunchIntentForPackage("com.sec.android.app.myfiles");
Uri uri = Uri.parse(rootPath);
if (intent != null) {
intent.setData(uri);
startActivity(intent);
}
As I said, it was easy for me because our clients have the same device but it may help others to find a workaround for their own situation.