For users who like "to work in this way",

[sitifan]

The grammatical entries in Practical English Usage are grouped into 28 Sections, each dealing with a major grammatical topic (e.g. present tenses, passives, nouns and noun phrases, prepositions, relative clauses). So the book can be used not only as a guide to particular usage problems, but also as a systematic reference grammar. For users who like to work in this way, each Section begins with one or two pages giving a general introduction to the grammatical topic, together with a list of common mistakes that are dealt with in the entries that follow. (my bold)
https://languageadvisor.net/oxford-practical-english-usage/
What does the expression in bold mean?

 

[emsr2d2]

It is addressing the people who like their textbooks to be laid out as a "systematic reference grammar" and feel that they learn best that way.

users who like to work = people who like to study (in this context)
in this way = using the previously mentioned type of textbook