Ruby on Rails has a nice feature to create nested parameters that help
with the organization of data in a form - parameters can be an
arbitrarily deep nested structure.

The way this structure is denoted is that when you construct a form the
field names have a special syntax which is parsed.

This plugin supports two syntaxes:

dot notation

        <input name="foo.bar.gorch" />

subscript notation

        <input name="foo[bar][gorch]" />

When reading query parameters from $c->req you can now access all the
items starting with "foo" as one entity using $c->req->param('foo');.
Each subitem, denoted by either the dot or the square brackets, will be
returned as a further deeper hashref.

WWW: https://metacpan.org/release/Catalyst-Plugin-Params-Nested