Can I create a section/sub-blog for a selection of my blog posts?

I’m creating an educational website, and I’m dividing my posts into subjects (it’s in Spanish so their names won’t match with their English counterparts –i.e. Math, Spanish language, Nature–).

However, sometimes I create posts that are within the same subject, but form by themselves some sort of ‘monographic’ –let’s say I have a post called ‘The letter A’, then another one called ‘The letter B’ and so on–. So I’d like for them to appear in the general ‘Spanish language blog index’ but make them also available as a pack, all of them together via button ‘click here to see all my post about letters’.

I’m thinking about creating a predefined search masked as a button, but I don’t know if there’s a better way.