Anyone have any best practice for grouping poems that are meant to be read in a particular order? List them in a series? What if they’re grouped in parts or sections, which themselves are ordered? Hierarchy is implied. Use [Work] has part [Work]?
Example:
On the bookshelf above my bed, between the pile of hopelessness with myths, fairy tales and religious texts and the pile of laziness of reading books consisting entirely of excerpts of other works, is the pile on which you can place this book. The pile consists of books that I have not added because the structure of the texts is too complicated for the current BB.
This includes books with poetry cycles like yours, but also anthologies where the works are sorted into chapters based on criteria. Or non-fiction books with articles/essays by different authors that make little sense without a structure.
What we would need is something like the “indices” and “headings” that discogs uses for outlining. But since this outline does not even exist in MB, as far as I know, this may take some time 
What to do?
The case is doubly complicated, as this is one of the cases where a collection must be seen as a “work” at the same time.
So we have the work “Spirits in Bondage”, which consists of three parts, which in turn are built up from individual poems, puuh [I secretly squint at the stack on the shelf, there is still a little space].
The easiest way (except the shelf of course) at the moment would be to enter only the three main parts (with part of main work relation) and in the “Notes”: Consists of poems number I-XXI. etc…
Of course you can also enter the single poems as sub parts of the parts of the main work (but where to put the roman numerals?), or you find your own shelf
OK, I was afraid that was going to be the answer. On my new shelf shall go this book, joining now a collection of translated short stories, where individual works cannot be traced to their translator(s).
Like @indy133 I think there are works that we simply can’t accommodate in BB at the moment. In my case, magazines, even literary magazines. But for poems, what I usually think is: can these poems be published separately (say, as part of an anthology)? If so, it’s still work adding them as separate poems to later join with as “part of” relationship when it becomes available.