Search specific layer of multidimensional matrix for range of values?

I have a layered matrix (3 layers) seen below and what I want to do is search for a range of values in the 2nd layer and then the 3rd layer and return the indices where the range of numbers are found. Lets say I have a variable dx that has a range of values and I want to return the indices in the 2nd and 3rd layer which have any of these values. Any ideas on how to do this? I was thinking of using the find command but am not sure how to use that with multidimensional matrices. Don't get bogged down by all of the code for setting up the matrices, it is just a simple 180x180 matrix with random integers and 2 layers with specified values in each. Thanks!

dx = -60:1:55

N11 = randi([1,500],45,45);
N12 = randi([25,1000],45,45);
N13 = randi([100,2200],45,45);
N14 = randi([5,700],45,45);
N21 = randi([100,500],45,45);
N22 = randi([800,3500],45,45);
N23 = randi([1000,10000],45,45);
N24 = randi([15,1000],45,45);
N31 = randi([250,900],45,45);
N32 = randi([5000,11000],45,45);
N33 = randi([1750,9000],45,45);
N34 = randi([25,890],45,45);
N41 = randi([2000,7500],45,45);
N42 = randi([200,2300],45,45);
N43 = randi([25,750],45,45);
N44 = randi([50,1323],45,45); 
N = [N11  N12  N13  N14;
     N21  N22  N23  N24;
     N31  N32  N33  N34;
     N41  N42  N43  N44];

H1 = -90:1:90;
H2 = H1(find(H1~=0));
V1 = -90:1:90;
V2 = V1';
V3 = V2(find(V2~=0));
N(:,:,2) = H2(ones(180,1),:);
N(:,:,3) = V3(:,ones(180,1));

Answer 1

[Thorsten]

idx2 = ismember(N(:,:,2), dx);
idx3 = ismember(N(:,:,3), dx);

[Andrew Poissant]

Perfect! Thanks