Image slider in content type based on selected images from another node (same content type)
I presume that the "We also Recommend" is manually entered by the user and that you are not using any specific logic to do it.

If that is the case then your approach would be to add an entity reference field in the content type and reference the nodes you want from there. 

Once you have that setup you can create a view to get the images from the nodes related the current view using relationship.

If you don't want to add the recommendations manually the you can use taxonomy to categories the contents and then display the images from the nodes tagged with the came taxonomy term.