Use the following code or follow the link

var tcc = ee.ImageCollection("projects/servir-mekong/UMD/tree_canopy"),
    tch = ee.ImageCollection("projects/servir-mekong/UMD/tree_height");

var tccThreshold = 10;
var tchThreshold = 5;
var year = 2010;

var tccImage = tcc.filterDate(year+'-01-01', year+'-12-31').first();
var tchImage = tch.filterDate(year+'-01-01', year+'-12-31').first();

var forestMap2010 = tccImage.gt(tccThreshold).and(tchImage.gt(tchThreshold));
forestMap2010 = forestMap2010.updateMask(forestMap2010);

Map.centerObject(forestMap2010);
Map.addLayer(forestMap2010, {palette: 'darkgreen'}, 'forestMap2010');