Rails: Find all children from the same generation - mysql

Question

In my application I have positions. Each position has one parent and many children positions. How can I navigate the tree and find all positions that are in the same generation?
Currently I have this:
def org_chart_level
ps = self
level = 10
while ps do
break if ps.reports_to == nil
ps = ps.reports_to
level += 10
end
if self.reports_to
siblings = self.reports_to.responsible_for
else
siblings = [self]
puts siblings
end
"#{level}-#{siblings.index(self) + 1}"
end
This almost works because it can give me the level of a position and it can tell me which sibling it is of the parent, but it cannot tell me which sibling it is in the generation.
Expected level for each position.
1.1
-2.1
-3.1
-2.2
-3.2
Actual level:
1.1
-2.1
-3.1
-2.2
-3.1

Answer 1

I ended up storing the positions generation in the database before it is saved.
before_save :find_generation
def find_generation
ps = self
i = 0
while ps do
break if ps.reports_to == nil
ps = ps.reports_to
i += 1
end
self.generation = i
end
And then when I need to generate the org chart level:
def org_chart_level
ps = self
level = 10
while ps do
break if ps.reports_to == nil
ps = ps.reports_to
level += 10
end
generation = organization.positions.where(generation: self.generation) #position belongs to organization.
"#{level}-#{generation.index(self) + 1}"
end