REST API Design: Subcollection inheriting an editable variation of a resource - api

Question

Bear with me, as I'm new to API Design and stackoverflow.
For my API design I have three main components:
key/value pairs (a singleton resource)
group (a collection of KVPs)
subgroup (a variation of the corresponding group)
In my API the user should be able to:
create, retrieve, update, and delete KVPs (basic CRUD actions)
organize KVPs into groups and access a listing of those groups
create subgroup variations of the groups that automatically inherit the parent groups' KVPs, and in those subgroups they can edit each KVPs data independently
For example, my Create a New Group request in my documentation looks like this:
{
"group": "age",
"kvps" : [
{
"key": "height",
"value": 5.2
}, {
"key": "weight",
"value": 150
}
],
"subgroups": [
"adult",
"teen",
"baby"
]
}
Using this as an example, I would like the subgroups "adult", "teen", and "baby" to have their own versions of the KVPs "height" and "weight" each with a different value (e.g. adult with a height of 6 and weight of 200, teen with a height of 5.2 and weight 140, etc.) that can be edited independently from each other.
My question: How should I structure my api so that a user could either:
have just editable kvps
have any number of editable kvps organized into any number of groups
or
have any number of editable kvps organized into groups and then further into subgroups
WITHOUT duplicating any of the data?
So far I have a uri structure like this:
/settings/kvps/{kvp_id} (CRUD on one single KVP)
/settings/groups/{group_id} (CRUD on one single group)
/settings/groups/{group_id}/kvps/{kvp_id}
/settings/groups/{group_id}/subgroups/{subgroup_id}
/settings/groups/{group_id}/subgroups/{subgroup_id}/kvps/{kvp_id}
So the kvps have 3 possible URIs, which seems messy to me, and from what I know editing the value of a kvp at
/settings/groups/1/subgroups/1/kvps/1
would also change its value at
/settings/groups/1/subgroups/2/kvps/1
/settings/groups/1/subgroups/3/kvps/1
/settings/groups/1/kvps/1
/settings/kvps/1
and so on, which is the opposite of what I want.
Any ideas?
Once again, I apologize if this is a very simple question that I am way off of, this is my first time designing an API.