A documentação de design do material tem um exemplo do Google Maps mostrando dois botões de ação flutuantes um ao lado do outro (na verdade, um acima do outro).

Como isso é feito? Eu tenho dois FABs em um layout de coordenador, mas eles acabam um sobre o outro, então você vê apenas um botão.

<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.CoordinatorLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <!-- Use ThemeOverlay to make the toolbar and tablayout text
             white -->
    <android.support.design.widget.AppBarLayout
        android:id="@+id/abl_top"
        android:layout_height="wrap_content"
        android:layout_width="match_parent"
        android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar">

        <android.support.v7.widget.Toolbar
            android:id="@+id/toolbar"
            android:fitsSystemWindows="true"
            android:layout_width="match_parent"
            android:layout_height="?attr/actionBarSize"
            app:popupTheme="@style/ThemeOverlay.AppCompat.Dark.ActionBar"/>
    </android.support.design.widget.AppBarLayout>

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical">

        <ImageView
            android:id="@+id/img_photo"
            android:layout_width="match_parent"
            android:layout_height="256dp"
            android:background="#C5C5C5"/>
        <EditText
            android:id="@+id/text_name"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_below="@id/img_baby"
            android:layout_alignParentStart="true"
            android:layout_alignParentLeft="true"
            android:hint="Name"
            android:drawableLeft="@drawable/ic_account"
            android:drawablePadding="20dp"
            android:textAppearance="?android:attr/textAppearanceSmall" />
        <TextView
            android:id="@+id/text_dob"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_below="@id/text_name"
            android:layout_alignParentStart="true"
            android:layout_alignParentLeft="true"
            android:hint="Date of birth"
            android:drawableLeft="@drawable/ic_cake"
            android:drawablePadding="20dp"
            style="@android:style/Widget.Holo.Spinner"/>

    </LinearLayout>

    <android.support.design.widget.FloatingActionButton
        android:id="@+id/fab_camera"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_margin="16dp"
        android:src="@drawable/ic_camera"
        android:clickable="true"
        app:fabSize="mini"
        app:layout_anchor="@id/img_photo"
        app:layout_anchorGravity="bottom|right|end"/>

    <android.support.design.widget.FloatingActionButton
        android:id="@+id/fab_gallery"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_margin="16dp"
        android:src="@drawable/ic_image"
        android:clickable="true"
        app:fabSize="mini"
        app:layout_anchor="@id/img_photo"
        app:layout_anchorGravity="bottom|right|end"/>

</android.support.design.widget.CoordinatorLayout>