issues: 968990058

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id node_id number title user state locked assignee milestone comments created_at updated_at closed_at author_association active_lock_reason draft pull_request body reactions performed_via_github_app state_reason repo type
968990058 MDU6SXNzdWU5Njg5OTAwNTg= 5700 Selection with multi-index and float32 values 4160723 closed 0     0 2021-08-12T14:55:11Z 2022-03-17T17:11:43Z 2022-03-17T17:11:43Z MEMBER      

I guess it's rather an edge case, but a similar issue than the one fixed in #3153 may occur with multi-indexes:

```python

foo_data = ['a', 'a', 'b', 'b'] bar_data = np.array([0.1, 0.2, 0.7, 0.9], dtype=np.float32) da = xr.DataArray([1, 2, 3, 4], dims="x", coords={"foo": ("x", foo_data), "bar": ("x", bar_data)}) da = da.set_index(x=["foo", "bar"]) ```

```python

da.sel(bar=0.1) KeyError: 0.1 ```

```python

da.sel(bar=np.array(0.1, dtype=np.float32).item()) <xarray.DataArray (foo: 1)> array([1]) Coordinates: * foo (foo) object 'a' ```

(xarray version: 0.18.2 as there's a regression introduced in 0.19.0 #5691)

 
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