How to reduce the time taken for the loop that finds all the sub structures which are of different depths and include last sub structures which are not structures

data_file=load(fname{1,indx}); %%%% Importing data file

NAMES = cellfun(@(x) strcat('data_file.',x),fieldnames(data_file),'UniformOutput',false) ;

for i=1:10000; %%%% loop to get all the structures

if isstruct(eval(NAMES{i,1})) >= 1

new_name=fieldnames(eval(NAMES{i,1}));

for k=1:length(fieldnames(eval(NAMES{i,1})));

new_NAMES(k,1)= cellfun(@(x) strcat([NAMES{i,1},'.'],x),cellstr(new_name{k,1}),'UniformOutput',false);

end

elseif isstruct(eval(NAMES{i,1})) < 1

end

NAMES=[NAMES; new_NAMES];

end

NAMES=unique(NAMES);

for i=1:10000; %%%% loop to get sub structures names if the last list of structures that are charecters or double

if isstruct(eval(NAMES{i,1})) < 1

new_name=cellstr(NAMES{i,1});

for k=1:length(NAMES{i,1})

new_NAMES= new_name;

end

elseif isstruct(eval(NAMES{i,1})) >= 1

new_name=fieldnames(eval(NAMES{i,1}));

for k=1:length(fieldnames(eval(NAMES{i,1})));

new_NAMES(k,1)= cellfun(@(x) strcat([NAMES{i,1},'.'],x),cellstr(new_name{k,1}),'UniformOutput',false);

end

end

NAMES=[NAMES; new_NAMES];

end

NAMES=unique(NAMES);