Sufferingg a little insomnia so thought i'd give OP a bit of a wordy guide
OP, if you have some rips of your own DVD or BR movies located within a directory on a portable hdd, then connect this hdd to the device that has Kodi installed (either a x86 based htpc, arm based android box, RPi, etc). Al boxes will have usb ports but if the hdd is not self powered you may need to connect the hdd through a powered usb hub as the usb port on the box may not provide the needed juice to spin up the hdd.
Then from Kodi itself, do what is mentioned in the message you see as shown in the picture you posted. Alernatively, just click <Videos> then <Files> then <Add videos...> and you will see an <Add video source> pop up.
With this <Add video source> pop up, you let Kodi know where your videos are located, that is specify a
video source. So from this <Add video source> pop up, browse to the 'directory' containing your movies, select it and then select <ok> within the pop up. A new <Set content> pop up appears where you specify what the source (where your DVD & BD movie directory) conatins. Since you should have only movies within this source, click <this directory contains...> and select <movies> then click in <Choose information provider> if you want something other than the default, but default should be good, click OK to finish.
Doing this
defines a source within Kodi which you have
speciied contians movies. And if connected to the internet, Kodi will then
interogate the information provider's web site and
fetch a bunch of meta data for all the movies within that source. Then Kodi will show your movies listed under the <Movie> lable shown with all the meta data that was fetched from the www.
Howver for this to work, you need to name your movies appropriately so look at
Naming video files/Movies (wiki) or better still read through
First_time_user (wiki)
Reading through the First time user and in particualr Adding videos to library sections of the wiki, you should realise that it's best to separate movies from tv shown and from music each into their own directories. In your travels through the wiki you will also realise that the source does not have to be a usb hdd connected to your kodi box but can also be any network drive accessable via your home network.
Read the wiki links and play around as you will better understand how to use Kodi. But remember Kodi Forum will not support you in accessing illegal streams via problematic add ons, so if that's your thing better go ask somewhere else. Reading
Official:Forum_rules (wiki) and
Banned_add-ons (wiki) should help you stay on the good side of the Kodi forum.