There are various ways of doing this in MODS depending upon at what level you are describing your materials. You could describe the chapter as the bibliographic resource with related Item for the larger work(s) or you could describe the larger work with related items for the parts. Since mods:relatedItem is defined to allow for all mods elements, you can include a full description at the relatedItem level.
A good way to do it is to describe the volume and use relatedItem type="constituent" for the chapter. The series could be in another relatedItem with type="series". However, in this case the volume may be better as type="host" rather than series (this isn't really a series), since it's part of another work.
If what you want to describe is this volume (obviously additional elements may be included):
<title>Clitophon, Republic, Timaeus, Critias</title>
[add additional title/part information for other chapters]
Alternatively, you can describe the resource with title Opera and have a relatedItem for the volume (type="constituent") and another relatedItem with type="constituent" for the chapter. Or describe the chapter with relatedItem type="host" for the volume and another relatedItem under it for the larger work.
From: Metadata Object Description Schema List [mailto:[log in to unmask]] On Behalf Of Nick Bart
Sent: Saturday, December 15, 2012 8:53 AM
To: [log in to unmask]
Subject: [MODS] How to mark chapter/book/multipart monograph/series
what would be the best practice of marking items such as
Plato. 1902. Republic. In Clitophon, Republic, Timaeus, Critias, vol. 4 of Opera, edited by J. Burnet, 327–621. Oxford Classical Texts. Oxford: Clarendon Press.
in MODS, i.e., a part, or chapter being part of a single volume being part of a multipart monograph being part of a series?