Returning values if it is greater than and less than to a specific value using UDF

Question

I am currently working on a UDF which returns and concatenates the headers if it is greater than and less than to a specific value. I’m not really good in Excel-Vba and what I got so far is this pathetic code which I couldn’t understand anymore. I would truly appreciate it if someone could help. Here's what i got so far:

Public Function greaterLessValue(Rng As Range, Rng2 As Range, greater, less)

Dim rngArr() As Variant
rngArr = Rng.value

For i = 1 To UBound(rngArr, 1)
    For j = 1 To UBound(rngArr, 2)
        If rngArr(i, j) = xVal Then
            For k = 1 To UBound(rngArr, 2)
                If rngArr(i, k) = Yval Then countRowAsso = countRowAsso + 1
            Next k
        End If
    Next j
Next i

End Function

If the value is greater than or equal to 5 and less than and equal to 10 it should return the same example bellow which concatenates the Header containing the specific value in the same column:

Answer 1

A.S.H makes a good point on confirming that the ranges hold the same number of elements/values/cells. I've used a different approach.

Option Explicit

Public Function greaterLessValue(rng1 As Range, rng2 As Range, _
                                 greater As Double, lesser As Double)

    Dim i As Long, j As Long
    Dim rngArr1 As Variant, rngArr2 As Variant

    rngArr1 = rng1.Value2
    rngArr2 = rng2.Value2
    greaterLessValue = ""

    'use for showing array extents
    'delete or comment out when function works
    Debug.Print LBound(rngArr1, 1) & " to " & UBound(rngArr1, 1)
    Debug.Print LBound(rngArr1, 2) & " to " & UBound(rngArr1, 2)

    'used to ensure that the ranges hold the same number of columns
    'only affects the 2nd rank when used with Preserve
    ReDim Preserve rngArr2(LBound(rngArr1, 1) To UBound(rngArr1, 1), _
                            LBound(rngArr1, 2) To UBound(rngArr1, 2))

    For i = LBound(rngArr1, 1) To UBound(rngArr1, 1)
        For j = LBound(rngArr1, 2) To UBound(rngArr1, 2)
            If IsNumeric(rngArr2(i, j)) Then
                If rngArr2(i, j) >= greater And rngArr2(i, j) <= lesser Then
                    greaterLessValue = greaterLessValue & _
                                       IIf(CBool(Len(greaterLessValue)), ", ", vbNullString) & _
                                       rngArr1(i, j)
                End If
            End If
        Next j
    Next i

End Function

Syntax as per the following image: