well it appears to be an insect rather than a slug. Slugs can strip tender young leaves completely, near the ground, and you will see the shiny trails of dried slime.
https://www.rhs.org.uk/advice/common-pest-identification-guide
Have a look at the labels on your chemicals. Do they say they kill leaf miners and caterpillars? Some are intended for killing greenfly.
You can see the squiggly yellow lines on the leaf, those are leaf miner, but the bigger holes look like caterpillar (not bee). You might find caterpillar webbing on it (somewhat like spiders web, but more tangled). I think the yellow spots are a sap-sucking insect, bigger than an aphid or thrip. Is this an ornamental cherry tree?
if this is an ornamental plant (not a food plant) I'd go for a systemic insecticide that will be drawn into the sap of the plant and remain poisonous to insects for a couple of weeks.
They might be dropping onto it from a higher tree, so look above.
I find Provanto Ultimate Bug Killer very good, but it seems expensive, you hardly get a thimbleful of concentrate so have to measure it out and dilute it with great care. A small pump-up hand sprayer (maybe a litre) will be suitable. Little disposable bottles with the ready-to-use mixture are poor value unless you only have a couple of houseplants. I use Roseclear more often.
Spray in the evening when there will be no rain or hot sun before the chemical has been absorbed. You have to spray enough to get every leaf wet, preferably on both surfaces, which a mist will do. If it drips off, you have applied too much.
note the pump on top. You can get various sizes from about 1 litre up. The brass or plastic nozzle is adjustable for fine or coarse spray, or jet, which will reach further if the plant is tall.